/*
 * Copyright 2007 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.zxing.qrcode.decoder;

/**
 * <p>See ISO 18004:2006, 6.5.1. This enum encapsulates the four error
 * correction levels defined by the QR code standard.</p>
 *
 * @author Sean Owen
 */
public class ErrorCorrectionLevel {

    /**
     * L = ~7% correction
     */
    public static ErrorCorrectionLevel L = new ErrorCorrectionLevel(0x01);
    /**
     * M = ~15% correction
     */
    public static ErrorCorrectionLevel M = new ErrorCorrectionLevel(0x00);
    /**
     * Q = ~25% correction
     */
    public static ErrorCorrectionLevel Q = new ErrorCorrectionLevel(0x03);
    /**
     * H = ~30% correction
     */
    public static ErrorCorrectionLevel H = new ErrorCorrectionLevel(0x02);
    private static final ErrorCorrectionLevel[] FOR_BITS = {M, L, H, Q};
    private final int bits;
    private int ordinal;

    ErrorCorrectionLevel(int bits) {
        this.bits = bits;
        if (bits == 0x00) {
            ordinal = 1;
        } else if (bits == 0x01) {
            ordinal = 0;
        } else if (bits == 0x02) {
            ordinal = 3;
        } else if (bits == 0x03) {
            ordinal = 2;
        }
    }

    public int getBits() {
        return bits;
    }

    /**
     * @param bits int containing the two bits encoding a QR Code's error
     * correction level
     * @return ErrorCorrectionLevel representing the encoded error correction
     * level
     */
    public static ErrorCorrectionLevel forBits(int bits) {
        if (bits < 0 || bits >= FOR_BITS.length) {
            throw new IllegalArgumentException();
        }
        return FOR_BITS[bits];
    }

    public int ordinal() {
        return ordinal;
    }
}
